Two bids for the same treatment unit can look far apart on paper and still be close once the permit and inspection work is added, or the reverse. Many cities and counties in Missouri require a permit for some plumbing or electrical work tied to a new water treatment unit, but the rules differ from one jurisdiction to the next. Some require a permit for any change to supply or drain lines. Others only care about the electrical outlet the unit plugs into. Your local building or plumbing office is the only place that can tell you what applies to your address.
Call the local office before you ask for bids
Ask three plain questions. Does a new treatment unit at my address need a permit? If so, which trades does it cover, plumbing, electrical, or both? Who is allowed to pull the permit, the licensed contractor or the homeowner? Write down the answers and the name of the person you spoke with, then give that same description to every installer you contact, so every bid covers the same scope.
Compare bids on the same permit terms
A bid that leaves out the permit and inspection is not comparable to one that includes them. Ask each provider to state on the quote whether the permit fee is included, passed through at cost, or paid by you directly. Ask whether the inspection fee is separate and whether the installer must be present for the inspection. If the bid is lower only because the permit is excluded, the difference belongs in your comparison, not in a footnote.
Ask about the schedule, not just the fee
Inspections have timing. Some inspectors need to see the work before walls are closed or before water is turned on. Ask the installer when the inspection will happen in the sequence of the job, how long the wait is to book it, and what happens to the crew if they must stop and wait. A delay can cost more than the permit itself, especially if you are without water service for a day while the work is on hold.
Settle who pays if the inspector asks for changes
If an inspector flags a problem, someone has to correct it and someone has to pay for the correction. Ask the provider to state in writing whether a correction required by the inspector is included in the quote or handled as a change order at extra cost. Ask whether the re-inspection fee is included. A clear answer now prevents an argument later about a required fix that was never part of the original scope.
Keep the paperwork
Once the permit is closed out, keep the permit number, the inspection record, and the final approval with your other equipment records. You will want them if you sell the home, file an insurance claim, or need to show a later technician what was installed and how it was approved.